As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE IN CRUISE FLIGHT, THE RT ENGINE BEGAN TO LOSE RPM. THE PILOT PUSHED THE PROPELLER CONTROL LEVER ALL THE WAY FORWARD TO MAX RPM WITH NO CHANGE. THE PILOT DESCENDED AND MADE AN UNEVENTFUL LANDING. THE RT ENGINE QUIT ON ROLL OUT AND THE RT PROPELLER WENT INTO FEATHER. THE PROPELLER GOVERNOR WAS REMOVED AND APPEARED TO HAVE AN INTERNAL FAILURE. A SERVICEABLE GOVERNOR WAS INSTALLED AND OPS CHECKED OK.